Aiitliors' Catalogue. 387 
diabases and norytes cutting the granites and showing themselves 
to be younger than the folding. 
Conformably underlying the quartzyte and amphibolyte beds, 
occur the gneisses. The gneiss series begins with a dense fine- 
grained gneiss and passes by insensible gradations into a less fine- 
grained and more highly metamorphosed grey feldspathic gneiss, 
which covers the greater part of the eastern pgrtion of the Vestana 
region. Interbedded with the gneisses are conformable layers of 
mica-schist, which show the structure and composition of sediments. 
The gneisses themselves have the chemical composition of quartz- 
diorytes and also show quartzes of the form common to the intelluric 
quartzes of efifusive rocks. The gneisses are therefore regarded as 
resulting from the mechanical destruction of a quartz-porphyryte-tufF. 
The southwestern and southern part of the area is occupied by a 
granite-gneiss. It is provisionally explained as an intrusive granite 
altered to a gneiss. 
All the rocks of the Vestana region show more or less the effects 
of pressure, though only locally are the effects marked. Contact- 
metamorphism, however, has widely and strongly affected the sedi- 
ments. In the quartzyte beds alone has this metamorpliism been 
obliterated by the subsequent tectonic movements. This folding, 
affecting granite and sediments alike, pressed down between the 
lower and more highly metamorphosed gneisses a small part of the 
mica-quartzyte, once more widely extended, and the highest member 
of the gneissic series, and thereby saved them from removal by 
erosion. 
The paper is accompanied by excellent photomicrographs and is a 
suggestive contribution to the understanding of the pre-Cambrian 
crystallines. The value of the petrographic study suffers some loss 
in the brevity of the English summary. F. b. 
MONTHLY AUTHORS' CATALOGUE 
OF American Geological Literature, 
Arranged Alphabetically.* 
Adams, F. D. 
The deformation of rocks under pressure. [Abstract.] (Eng. and 
Mining Jour., vol. 65, p. 522, Apr. 30, 1898.) 
Adams, G. I. 
Physiography of southeastern Kansas. (Kansas Univ. Quarterly, 
vol. 7,' ser. A, pp. 87-102, Apr. 1898.) 
♦This list includes titles of articles received up to the 20th of the preceding 
month, including general geoloxy, physiography, paleontology, petrology ana 
mineralogy. 
